HvA investigated differences between European and Asian chargers

The Amsterdam University of Applied Sciences (HvA) tested laptop chargers on behalf of FHI using EMC guidelines. The aim of these tests was to investigate whether there were differences between regular European and cheap Asian systems. Did cheaper models produce interference or noise and could potentially lead to dangerous situations? Although all tested chargers met the CE mark and NEN-EN-55022, there were certainly differences to be noticed.

By Frank van de Ven

The tested chargers from Europe were ordered from large online retailers such as Bol.com and CoolBlue. Chargers from Asia came from AliExpress and AliBaba. According to the packaging, all products met the requirements of the CE mark. FHI wondered whether this was the case given the pricing. The trade association commissioned HvA to investigate these systems and to see what the biggest (quality) differences were. If there is a potentially dangerous situation, that is a matter for Agentschap Telecom. 

Students Boris van Wessel and Youness Azoubairi, led by lecturer Dr. Cees Keyer, started working on this study. The aim of this study was to examine the level playing field. Products from Asia are often cheaper than European goods, but what is the quality actually like? The study did not show any major differences in quality, although it turned out that the Asian chargers cause more noise and interference. An order also arrived damaged and there is no guarantee. Returning a package to China costs more than buying a new, European product.

Noticeable difference
Four universal chargers were used for the test with a power between 60 and 65 Watts at a current of 3 to 3.25 A. The selected chargers were chosen based on their popularity. The Safe Mains Voltage Monitor was used for the test. This system was developed to safely measure the current drawn by the charger using a current clamp. To ensure that all chargers were exposed to the same power requirements, an electronic load was used during the measurements. A probe measured the minimum and maximum output voltage of the chargers.

When preparing the chargers for the measurements, the team discovered a noticeable difference in weight between the Asian and European chargers. The Asian loaders weighed significantly less than the European systems. Both the imported and European chargers have a mains spectrum that never exceeded the quasi-peak limits of NEN EN-55022. All tested equipment met the EMC standards.

Noise on the power grid
There were minimal differences in current between the two tested European chargers. This did not apply to the Asian models, where there were large differences between the minimum and maximum output voltage. Not only were there large differences between them. Compared to the European chargers, the output voltage of the Asian systems was very high.

The large differences between minimum and maximum output voltages are a point of attention for Asian chargers. All measured chargers meet the NEN-EN-55022 requirements. However, there are differences between the amount of noise and the voltages generated. The quality of Asian chargers with regard to EMC emissions depends on the model. A large difference in noise was measured on the power grid between the models. This does not apply to European chargers and the quality of the tested systems is very close.

The results of the study have been bundled in a white paper. This document is intended to make people aware of the importance of the EMC sector. The results of the study will be discussed in an exclusive lunch session for members of the Industrial Electronics sector. Videos will also be released later in which the study is discussed. A follow-up study is also planned in which increasing awareness is central. The white paper can be requested from Marc Berkouwer by sending an email to marc.berkouwer@fhi.nl.